Sorry im a little late but here's how i did it.
Hope this helps! :)
Answer:
The answer is option 1.
Step-by-step explanation:
In order to simplify the expressions, you have to collect like terms :
3a² + 9ab + 5 - 4a² - 4ab + 3
= (3a² - 4a²) + (9ab - 4ab) + (5 + 3)
= -a² + 5ab + 8
7x w x 13=546
(7x13)*w= 546
91w=546
91w/91= 546/91
w= 6
the width is 6cm
5.7082,5.009,5.09,5.7
